Location systems are known for providing location estimations for tracking the location of an object, for example, a mobile device, within a region, for example, a building, plant, or other facility. For example, many known location systems include location anchors (LA).
In many known location systems, an object can transmit a probe request to a location anchor and receive a probe response from the location anchor. The object can then measure the received signal strength indication (RSSI) of the probe response to estimate the distance to the location anchor.
The following documents disclose exemplary location systems that include exemplary location anchors: U.S. Pat. No. 7,603,129 titled “Localization Identification System for Wireless Devices”; U.S. Pat. No. 8,442,801 titled “Wireless Location-Based System for Detecting Hazardous Conditions”; U.S. Publication No. 2013/0155102 titled “Systems and Methods of Accuracy Mapping in a Location Tracking System”; U.S. Publication No. 2011/0161885 titled “Wireless Location-Based System and Method for Detecting Hazardous and Non-Hazardous Conditions”; and U.S. Publication No. 2014/0051459 titled “System and Method for Improved Location System Accuracy”. Each of the above-identified documents is assigned to the assignee hereof and is hereby incorporated by reference.
Notwithstanding the above, known location systems can provide location estimations with only limited accuracy. To increase location accuracy, known location systems have added infrastructure in the form of more location anchors. However, such systems have limits, both in terms of accuracy and infrastructure.
In view of the above, there is a continuing, ongoing need for a system and method for improved location accuracy, especially in regions where additional accuracy is desirable.